1 // SPDX-License-Identifier: GPL-2.0-or-later <<
2 /* 1 /*
3 * OpenRISC irq.c !! 2 * arch/ppc/kernel/irq.c
4 * 3 *
5 * Linux architectural port borrowing liberall !! 4 * Derived from arch/i386/kernel/irq.c
6 * others. All original copyrights apply as p !! 5 * Copyright (C) 1992 Linus Torvalds
7 * declaration. !! 6 * Adapted from arch/i386 by Gary Thomas
>> 7 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
>> 8 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
>> 9 * Copyright (C) 1996-2001 Cort Dougan
>> 10 * Adapted for Power Macintosh by Paul Mackerras
>> 11 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
>> 12 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
8 * 13 *
9 * Modifications for the OpenRISC architecture !! 14 * This file contains the code used by various IRQ handling routines:
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@s !! 15 * asking for different IRQ's should be done through these routines
>> 16 * instead of just grabbing them. Thus setups with different IRQ numbers
>> 17 * shouldn't result in any weird surprises, and installing new handlers
>> 18 * should be easier.
>> 19 *
>> 20 * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
>> 21 * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
>> 22 * mask register (of which only 16 are defined), hence the weird shifting
>> 23 * and compliment of the cached_irq_mask. I want to be able to stuff
>> 24 * this right into the SIU SMASK register.
>> 25 * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
>> 26 * to reduce code space and undefined function references.
11 */ 27 */
12 28
>> 29
>> 30 #include <linux/ptrace.h>
>> 31 #include <linux/errno.h>
>> 32 #include <linux/threads.h>
>> 33 #include <linux/kernel_stat.h>
>> 34 #include <linux/signal.h>
>> 35 #include <linux/sched.h>
>> 36 #include <linux/ioport.h>
13 #include <linux/interrupt.h> 37 #include <linux/interrupt.h>
>> 38 #include <linux/timex.h>
>> 39 #include <linux/config.h>
14 #include <linux/init.h> 40 #include <linux/init.h>
15 #include <linux/ftrace.h> !! 41 #include <linux/slab.h>
>> 42 #include <linux/pci.h>
>> 43 #include <linux/delay.h>
16 #include <linux/irq.h> 44 #include <linux/irq.h>
17 #include <linux/irqchip.h> !! 45 #include <linux/proc_fs.h>
18 #include <linux/export.h> !! 46 #include <linux/random.h>
19 #include <linux/irqflags.h> !! 47
>> 48 #include <asm/uaccess.h>
>> 49 #include <asm/bitops.h>
>> 50 #include <asm/system.h>
>> 51 #include <asm/io.h>
>> 52 #include <asm/pgtable.h>
>> 53 #include <asm/irq.h>
>> 54 #include <asm/cache.h>
>> 55 #include <asm/prom.h>
>> 56 #include <asm/ptrace.h>
>> 57
>> 58 #define NR_MASK_WORDS ((NR_IRQS + 31) / 32)
>> 59
>> 60 extern atomic_t ipi_recv;
>> 61 extern atomic_t ipi_sent;
>> 62 void enable_irq(unsigned int irq_nr);
>> 63 void disable_irq(unsigned int irq_nr);
>> 64
>> 65 static void register_irq_proc (unsigned int irq);
>> 66
>> 67 #define MAXCOUNT 10000000
>> 68
>> 69 irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned =
>> 70 { [0 ... NR_IRQS-1] = { 0, NULL, NULL, 0, SPIN_LOCK_UNLOCKED}};
>> 71
>> 72 int ppc_spurious_interrupts = 0;
>> 73 struct irqaction *ppc_irq_action[NR_IRQS];
>> 74 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
>> 75 unsigned long ppc_lost_interrupts[NR_MASK_WORDS];
>> 76 atomic_t ppc_n_lost_interrupts;
>> 77
>> 78 /* nasty hack for shared irq's since we need to do kmalloc calls but
>> 79 * can't very early in the boot when we need to do a request irq.
>> 80 * this needs to be removed.
>> 81 * -- Cort
>> 82 */
>> 83 #define IRQ_KMALLOC_ENTRIES 8
>> 84 static int cache_bitmask = 0;
>> 85 static struct irqaction malloc_cache[IRQ_KMALLOC_ENTRIES];
>> 86 extern int mem_init_done;
>> 87
>> 88 #if defined(CONFIG_TAU_INT)
>> 89 extern int tau_interrupts(unsigned long cpu);
>> 90 extern int tau_initialized;
>> 91 #endif
>> 92
>> 93 void *irq_kmalloc(size_t size, int pri)
>> 94 {
>> 95 unsigned int i;
>> 96 if ( mem_init_done )
>> 97 return kmalloc(size,pri);
>> 98 for ( i = 0; i < IRQ_KMALLOC_ENTRIES ; i++ )
>> 99 if ( ! ( cache_bitmask & (1<<i) ) )
>> 100 {
>> 101 cache_bitmask |= (1<<i);
>> 102 return (void *)(&malloc_cache[i]);
>> 103 }
>> 104 return 0;
>> 105 }
>> 106
>> 107 void irq_kfree(void *ptr)
>> 108 {
>> 109 unsigned int i;
>> 110 for ( i = 0 ; i < IRQ_KMALLOC_ENTRIES ; i++ )
>> 111 if ( ptr == &malloc_cache[i] )
>> 112 {
>> 113 cache_bitmask &= ~(1<<i);
>> 114 return;
>> 115 }
>> 116 kfree(ptr);
>> 117 }
>> 118
>> 119 int
>> 120 setup_irq(unsigned int irq, struct irqaction * new)
>> 121 {
>> 122 int shared = 0;
>> 123 unsigned long flags;
>> 124 struct irqaction *old, **p;
>> 125 irq_desc_t *desc = irq_desc + irq;
>> 126
>> 127 /*
>> 128 * Some drivers like serial.c use request_irq() heavily,
>> 129 * so we have to be careful not to interfere with a
>> 130 * running system.
>> 131 */
>> 132 if (new->flags & SA_SAMPLE_RANDOM) {
>> 133 /*
>> 134 * This function might sleep, we want to call it first,
>> 135 * outside of the atomic block.
>> 136 * Yes, this might clear the entropy pool if the wrong
>> 137 * driver is attempted to be loaded, without actually
>> 138 * installing a new handler, but is this really a problem,
>> 139 * only the sysadmin is able to do this.
>> 140 */
>> 141 rand_initialize_irq(irq);
>> 142 }
>> 143
>> 144 /*
>> 145 * The following block of code has to be executed atomically
>> 146 */
>> 147 spin_lock_irqsave(&desc->lock,flags);
>> 148 p = &desc->action;
>> 149 if ((old = *p) != NULL) {
>> 150 /* Can't share interrupts unless both agree to */
>> 151 if (!(old->flags & new->flags & SA_SHIRQ)) {
>> 152 spin_unlock_irqrestore(&desc->lock,flags);
>> 153 return -EBUSY;
>> 154 }
>> 155
>> 156 /* add new interrupt at end of irq queue */
>> 157 do {
>> 158 p = &old->next;
>> 159 old = *p;
>> 160 } while (old);
>> 161 shared = 1;
>> 162 }
>> 163
>> 164 *p = new;
>> 165
>> 166 if (!shared) {
>> 167 desc->depth = 0;
>> 168 desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING);
>> 169 unmask_irq(irq);
>> 170 }
>> 171 spin_unlock_irqrestore(&desc->lock,flags);
>> 172
>> 173 register_irq_proc(irq);
>> 174 return 0;
>> 175 }
20 176
21 /* read interrupt enabled status */ !! 177 void free_irq(unsigned int irq, void* dev_id)
22 unsigned long arch_local_save_flags(void) <<
23 { 178 {
24 return mfspr(SPR_SR) & (SPR_SR_IEE|SPR !! 179 irq_desc_t *desc;
>> 180 struct irqaction **p;
>> 181 unsigned long flags;
>> 182
>> 183 desc = irq_desc + irq;
>> 184 spin_lock_irqsave(&desc->lock,flags);
>> 185 p = &desc->action;
>> 186 for (;;) {
>> 187 struct irqaction * action = *p;
>> 188 if (action) {
>> 189 struct irqaction **pp = p;
>> 190 p = &action->next;
>> 191 if (action->dev_id != dev_id)
>> 192 continue;
>> 193
>> 194 /* Found it - now remove it from the list of entries */
>> 195 *pp = action->next;
>> 196 if (!desc->action) {
>> 197 desc->status |= IRQ_DISABLED;
>> 198 mask_irq(irq);
>> 199 }
>> 200 spin_unlock_irqrestore(&desc->lock,flags);
>> 201
>> 202 #ifdef CONFIG_SMP
>> 203 /* Wait to make sure it's not being used on another CPU */
>> 204 while (desc->status & IRQ_INPROGRESS)
>> 205 barrier();
>> 206 #endif
>> 207 irq_kfree(action);
>> 208 return;
>> 209 }
>> 210 printk("Trying to free free IRQ%d\n",irq);
>> 211 spin_unlock_irqrestore(&desc->lock,flags);
>> 212 break;
>> 213 }
>> 214 return;
25 } 215 }
26 EXPORT_SYMBOL(arch_local_save_flags); <<
27 216
28 /* set interrupt enabled status */ !! 217 int request_irq(unsigned int irq, void (*handler)(int, void *, struct pt_regs *),
29 void arch_local_irq_restore(unsigned long flag !! 218 unsigned long irqflags, const char * devname, void *dev_id)
30 { 219 {
31 mtspr(SPR_SR, ((mfspr(SPR_SR) & ~(SPR_ !! 220 struct irqaction *action;
>> 221 int retval;
>> 222
>> 223 if (irq >= NR_IRQS)
>> 224 return -EINVAL;
>> 225 if (!handler)
>> 226 {
>> 227 /*
>> 228 * free_irq() used to be implemented as a call to
>> 229 * request_irq() with handler being NULL. Now we have
>> 230 * a real free_irq() but need to allow the old behavior
>> 231 * for old code that hasn't caught up yet.
>> 232 * -- Cort <cort@fsmlabs.com>
>> 233 */
>> 234 free_irq(irq, dev_id);
>> 235 return 0;
>> 236 }
>> 237
>> 238 action = (struct irqaction *)
>> 239 irq_kmalloc(sizeof(struct irqaction), GFP_KERNEL);
>> 240 if (!action) {
>> 241 printk(KERN_ERR "irq_kmalloc() failed for irq %d !\n", irq);
>> 242 return -ENOMEM;
>> 243 }
>> 244
>> 245 action->handler = handler;
>> 246 action->flags = irqflags;
>> 247 action->mask = 0;
>> 248 action->name = devname;
>> 249 action->dev_id = dev_id;
>> 250 action->next = NULL;
>> 251
>> 252 retval = setup_irq(irq, action);
>> 253 if (retval)
>> 254 {
>> 255 kfree(action);
>> 256 return retval;
>> 257 }
>> 258
>> 259 return 0;
>> 260 }
>> 261
>> 262 /*
>> 263 * Generic enable/disable code: this just calls
>> 264 * down into the PIC-specific version for the actual
>> 265 * hardware disable after having gotten the irq
>> 266 * controller lock.
>> 267 */
>> 268
>> 269 /**
>> 270 * disable_irq_nosync - disable an irq without waiting
>> 271 * @irq: Interrupt to disable
>> 272 *
>> 273 * Disable the selected interrupt line. Disables of an interrupt
>> 274 * stack. Unlike disable_irq(), this function does not ensure existing
>> 275 * instances of the IRQ handler have completed before returning.
>> 276 *
>> 277 * This function may be called from IRQ context.
>> 278 */
>> 279
>> 280 void disable_irq_nosync(unsigned int irq)
>> 281 {
>> 282 irq_desc_t *desc = irq_desc + irq;
>> 283 unsigned long flags;
>> 284
>> 285 spin_lock_irqsave(&desc->lock, flags);
>> 286 if (!desc->depth++) {
>> 287 if (!(desc->status & IRQ_PER_CPU))
>> 288 desc->status |= IRQ_DISABLED;
>> 289 mask_irq(irq);
>> 290 }
>> 291 spin_unlock_irqrestore(&desc->lock, flags);
>> 292 }
>> 293
>> 294 /**
>> 295 * disable_irq - disable an irq and wait for completion
>> 296 * @irq: Interrupt to disable
>> 297 *
>> 298 * Disable the selected interrupt line. Disables of an interrupt
>> 299 * stack. That is for two disables you need two enables. This
>> 300 * function waits for any pending IRQ handlers for this interrupt
>> 301 * to complete before returning. If you use this function while
>> 302 * holding a resource the IRQ handler may need you will deadlock.
>> 303 *
>> 304 * This function may be called - with care - from IRQ context.
>> 305 */
>> 306
>> 307 void disable_irq(unsigned int irq)
>> 308 {
>> 309 disable_irq_nosync(irq);
>> 310
>> 311 if (!local_irq_count(smp_processor_id())) {
>> 312 do {
>> 313 barrier();
>> 314 } while (irq_desc[irq].status & IRQ_INPROGRESS);
>> 315 }
>> 316 }
>> 317
>> 318 /**
>> 319 * enable_irq - enable interrupt handling on an irq
>> 320 * @irq: Interrupt to enable
>> 321 *
>> 322 * Re-enables the processing of interrupts on this IRQ line
>> 323 * providing no disable_irq calls are now in effect.
>> 324 *
>> 325 * This function may be called from IRQ context.
>> 326 */
>> 327
>> 328 void enable_irq(unsigned int irq)
>> 329 {
>> 330 irq_desc_t *desc = irq_desc + irq;
>> 331 unsigned long flags;
>> 332
>> 333 spin_lock_irqsave(&desc->lock, flags);
>> 334 switch (desc->depth) {
>> 335 case 1: {
>> 336 unsigned int status = desc->status & ~IRQ_DISABLED;
>> 337 desc->status = status;
>> 338 if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
>> 339 desc->status = status | IRQ_REPLAY;
>> 340 hw_resend_irq(desc->handler,irq);
>> 341 }
>> 342 unmask_irq(irq);
>> 343 /* fall-through */
>> 344 }
>> 345 default:
>> 346 desc->depth--;
>> 347 break;
>> 348 case 0:
>> 349 printk("enable_irq(%u) unbalanced\n", irq);
>> 350 }
>> 351 spin_unlock_irqrestore(&desc->lock, flags);
>> 352 }
>> 353
>> 354 int get_irq_list(char *buf)
>> 355 {
>> 356 int i, len = 0, j;
>> 357 struct irqaction * action;
>> 358
>> 359 len += sprintf(buf+len, " ");
>> 360 for (j=0; j<smp_num_cpus; j++)
>> 361 len += sprintf(buf+len, "CPU%d ",j);
>> 362 *(char *)(buf+len++) = '\n';
>> 363
>> 364 for (i = 0 ; i < NR_IRQS ; i++) {
>> 365 action = irq_desc[i].action;
>> 366 if ( !action || !action->handler )
>> 367 continue;
>> 368 len += sprintf(buf+len, "%3d: ", i);
>> 369 #ifdef CONFIG_SMP
>> 370 for (j = 0; j < smp_num_cpus; j++)
>> 371 len += sprintf(buf+len, "%10u ",
>> 372 kstat.irqs[cpu_logical_map(j)][i]);
>> 373 #else
>> 374 len += sprintf(buf+len, "%10u ", kstat_irqs(i));
>> 375 #endif /* CONFIG_SMP */
>> 376 if ( irq_desc[i].handler )
>> 377 len += sprintf(buf+len, " %s ", irq_desc[i].handler->typename );
>> 378 else
>> 379 len += sprintf(buf+len, " None ");
>> 380 len += sprintf(buf+len, "%s", (irq_desc[i].status & IRQ_LEVEL) ? "Level " : "Edge ");
>> 381 len += sprintf(buf+len, " %s",action->name);
>> 382 for (action=action->next; action; action = action->next) {
>> 383 len += sprintf(buf+len, ", %s", action->name);
>> 384 }
>> 385 len += sprintf(buf+len, "\n");
>> 386 }
>> 387 #ifdef CONFIG_TAU_INT
>> 388 if (tau_initialized){
>> 389 len += sprintf(buf+len, "TAU: ");
>> 390 for (j = 0; j < smp_num_cpus; j++)
>> 391 len += sprintf(buf+len, "%10u ",
>> 392 tau_interrupts(j));
>> 393 len += sprintf(buf+len, " PowerPC Thermal Assist (cpu temp)\n");
>> 394 }
>> 395 #endif
>> 396 #ifdef CONFIG_SMP
>> 397 /* should this be per processor send/receive? */
>> 398 len += sprintf(buf+len, "IPI (recv/sent): %10u/%u\n",
>> 399 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
>> 400 #endif
>> 401 len += sprintf(buf+len, "BAD: %10u\n", ppc_spurious_interrupts);
>> 402 return len;
>> 403 }
>> 404
>> 405 static inline void
>> 406 handle_irq_event(int irq, struct pt_regs *regs, struct irqaction *action)
>> 407 {
>> 408 int status = 0;
>> 409
>> 410 if (!(action->flags & SA_INTERRUPT))
>> 411 __sti();
>> 412
>> 413 do {
>> 414 status |= action->flags;
>> 415 action->handler(irq, action->dev_id, regs);
>> 416 action = action->next;
>> 417 } while (action);
>> 418 if (status & SA_SAMPLE_RANDOM)
>> 419 add_interrupt_randomness(irq);
>> 420 __cli();
>> 421 }
>> 422
>> 423 /*
>> 424 * Eventually, this should take an array of interrupts and an array size
>> 425 * so it can dispatch multiple interrupts.
>> 426 */
>> 427 void ppc_irq_dispatch_handler(struct pt_regs *regs, int irq)
>> 428 {
>> 429 int status;
>> 430 struct irqaction *action;
>> 431 int cpu = smp_processor_id();
>> 432 irq_desc_t *desc = &irq_desc[irq];
>> 433
>> 434 kstat.irqs[cpu][irq]++;
>> 435 spin_lock(&desc->lock);
>> 436 ack_irq(irq);
>> 437 /*
>> 438 REPLAY is when Linux resends an IRQ that was dropped earlier
>> 439 WAITING is used by probe to mark irqs that are being tested
>> 440 */
>> 441 status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
>> 442 if (!(status & IRQ_PER_CPU))
>> 443 status |= IRQ_PENDING; /* we _want_ to handle it */
>> 444
>> 445 /*
>> 446 * If the IRQ is disabled for whatever reason, we cannot
>> 447 * use the action we have.
>> 448 */
>> 449 action = NULL;
>> 450 if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
>> 451 action = desc->action;
>> 452 if (!action || !action->handler) {
>> 453 ppc_spurious_interrupts++;
>> 454 printk(KERN_DEBUG "Unhandled interrupt %x, disabled\n", irq);
>> 455 /* We can't call disable_irq here, it would deadlock */
>> 456 ++desc->depth;
>> 457 desc->status |= IRQ_DISABLED;
>> 458 mask_irq(irq);
>> 459 /* This is a real interrupt, we have to eoi it,
>> 460 so we jump to out */
>> 461 goto out;
>> 462 }
>> 463 status &= ~IRQ_PENDING; /* we commit to handling */
>> 464 if (!(status & IRQ_PER_CPU))
>> 465 status |= IRQ_INPROGRESS; /* we are handling it */
>> 466 }
>> 467 desc->status = status;
>> 468
>> 469 /*
>> 470 * If there is no IRQ handler or it was disabled, exit early.
>> 471 Since we set PENDING, if another processor is handling
>> 472 a different instance of this same irq, the other processor
>> 473 will take care of it.
>> 474 */
>> 475 if (!action)
>> 476 goto out;
>> 477
>> 478
>> 479 /*
>> 480 * Edge triggered interrupts need to remember
>> 481 * pending events.
>> 482 * This applies to any hw interrupts that allow a second
>> 483 * instance of the same irq to arrive while we are in do_IRQ
>> 484 * or in the handler. But the code here only handles the _second_
>> 485 * instance of the irq, not the third or fourth. So it is mostly
>> 486 * useful for irq hardware that does not mask cleanly in an
>> 487 * SMP environment.
>> 488 */
>> 489 for (;;) {
>> 490 spin_unlock(&desc->lock);
>> 491 handle_irq_event(irq, regs, action);
>> 492 spin_lock(&desc->lock);
>> 493
>> 494 if (!(desc->status & IRQ_PENDING))
>> 495 break;
>> 496 desc->status &= ~IRQ_PENDING;
>> 497 }
>> 498 desc->status &= ~IRQ_INPROGRESS;
>> 499 out:
>> 500 /*
>> 501 * The ->end() handler has to deal with interrupts which got
>> 502 * disabled while the handler was running.
>> 503 */
>> 504 if (desc->handler) {
>> 505 if (desc->handler->end)
>> 506 desc->handler->end(irq);
>> 507 else if (desc->handler->enable)
>> 508 desc->handler->enable(irq);
>> 509 }
>> 510
>> 511 #ifdef CONFIG_DBOX2
>> 512 /*
>> 513 * Interrupts marked as oneshot are level
>> 514 * triggered. We disable them here for onboard
>> 515 * hardware which can not be configured to
>> 516 * generate edge triggered interrupts due to
>> 517 * lack of documentation.
>> 518 */
>> 519 if ((action) && (action->flags & SA_ONESHOT))
>> 520 disable_irq_nosync(irq);
>> 521 #endif
>> 522
>> 523 spin_unlock(&desc->lock);
>> 524 }
>> 525
>> 526 int do_IRQ(struct pt_regs *regs)
>> 527 {
>> 528 int cpu = smp_processor_id();
>> 529 int irq, first = 1;
>> 530 hardirq_enter( cpu );
>> 531
>> 532 /*
>> 533 * Every platform is required to implement ppc_md.get_irq.
>> 534 * This function will either return an irq number or -1 to
>> 535 * indicate there are no more pending. But the first time
>> 536 * through the loop this means there wasn't an IRQ pending.
>> 537 * The value -2 is for buggy hardware and means that this IRQ
>> 538 * has already been handled. -- Tom
>> 539 */
>> 540 while ((irq = ppc_md.get_irq(regs)) >= 0) {
>> 541 ppc_irq_dispatch_handler(regs, irq);
>> 542 first = 0;
>> 543 }
>> 544 if (irq != -2 && first)
>> 545 /* That's not SMP safe ... but who cares ? */
>> 546 ppc_spurious_interrupts++;
>> 547 hardirq_exit( cpu );
>> 548
>> 549 if (softirq_pending(cpu))
>> 550 do_softirq();
>> 551 return 1; /* lets ret_from_int know we can do checks */
>> 552 }
>> 553
>> 554 unsigned long probe_irq_on (void)
>> 555 {
>> 556 return 0;
>> 557 }
>> 558
>> 559 int probe_irq_off (unsigned long irqs)
>> 560 {
>> 561 return 0;
>> 562 }
>> 563
>> 564 unsigned int probe_irq_mask(unsigned long irqs)
>> 565 {
>> 566 return 0;
32 } 567 }
33 EXPORT_SYMBOL(arch_local_irq_restore); <<
34 568
35 void __init init_IRQ(void) 569 void __init init_IRQ(void)
36 { 570 {
37 irqchip_init(); !! 571 static int once = 0;
>> 572
>> 573 if ( once )
>> 574 return;
>> 575 else
>> 576 once++;
>> 577
>> 578 ppc_md.init_IRQ();
>> 579 }
>> 580
>> 581 #ifdef CONFIG_SMP
>> 582 unsigned char global_irq_holder = NO_PROC_ID;
>> 583 unsigned volatile long global_irq_lock; /* pendantic :long for set_bit--RR*/
>> 584 atomic_t global_irq_count;
>> 585
>> 586 atomic_t global_bh_count;
>> 587
>> 588 static void show(char * str)
>> 589 {
>> 590 int i;
>> 591 unsigned long *stack;
>> 592 int cpu = smp_processor_id();
>> 593
>> 594 printk("\n%s, CPU %d:\n", str, cpu);
>> 595 printk("irq: %d [%d %d]\n",
>> 596 atomic_read(&global_irq_count),
>> 597 local_irq_count(0),
>> 598 local_irq_count(1));
>> 599 printk("bh: %d [%d %d]\n",
>> 600 atomic_read(&global_bh_count),
>> 601 local_bh_count(0),
>> 602 local_bh_count(1));
>> 603 stack = (unsigned long *) &str;
>> 604 for (i = 40; i ; i--) {
>> 605 unsigned long x = *++stack;
>> 606 if (x > (unsigned long) &init_task_union && x < (unsigned long) &vsprintf) {
>> 607 printk("<[%08lx]> ", x);
>> 608 }
>> 609 }
>> 610 }
>> 611
>> 612 static inline void wait_on_bh(void)
>> 613 {
>> 614 int count = MAXCOUNT;
>> 615 do {
>> 616 if (!--count) {
>> 617 show("wait_on_bh");
>> 618 count = ~0;
>> 619 }
>> 620 /* nothing .. wait for the other bh's to go away */
>> 621 } while (atomic_read(&global_bh_count) != 0);
>> 622 }
>> 623
>> 624
>> 625 static inline void wait_on_irq(int cpu)
>> 626 {
>> 627 int count = MAXCOUNT;
>> 628
>> 629 for (;;) {
>> 630
>> 631 /*
>> 632 * Wait until all interrupts are gone. Wait
>> 633 * for bottom half handlers unless we're
>> 634 * already executing in one..
>> 635 */
>> 636 if (!atomic_read(&global_irq_count)) {
>> 637 if (local_bh_count(cpu)
>> 638 || !atomic_read(&global_bh_count))
>> 639 break;
>> 640 }
>> 641
>> 642 /* Duh, we have to loop. Release the lock to avoid deadlocks */
>> 643 clear_bit(0,&global_irq_lock);
>> 644
>> 645 for (;;) {
>> 646 if (!--count) {
>> 647 show("wait_on_irq");
>> 648 count = ~0;
>> 649 }
>> 650 __sti();
>> 651 /* don't worry about the lock race Linus found
>> 652 * on intel here. -- Cort
>> 653 */
>> 654 __cli();
>> 655 if (atomic_read(&global_irq_count))
>> 656 continue;
>> 657 if (global_irq_lock)
>> 658 continue;
>> 659 if (!local_bh_count(cpu)
>> 660 && atomic_read(&global_bh_count))
>> 661 continue;
>> 662 if (!test_and_set_bit(0,&global_irq_lock))
>> 663 break;
>> 664 }
>> 665 }
>> 666 }
>> 667
>> 668 /*
>> 669 * This is called when we want to synchronize with
>> 670 * bottom half handlers. We need to wait until
>> 671 * no other CPU is executing any bottom half handler.
>> 672 *
>> 673 * Don't wait if we're already running in an interrupt
>> 674 * context or are inside a bh handler.
>> 675 */
>> 676 void synchronize_bh(void)
>> 677 {
>> 678 if (atomic_read(&global_bh_count) && !in_interrupt())
>> 679 wait_on_bh();
>> 680 }
>> 681
>> 682 /*
>> 683 * This is called when we want to synchronize with
>> 684 * interrupts. We may for example tell a device to
>> 685 * stop sending interrupts: but to make sure there
>> 686 * are no interrupts that are executing on another
>> 687 * CPU we need to call this function.
>> 688 */
>> 689 void synchronize_irq(void)
>> 690 {
>> 691 if (atomic_read(&global_irq_count)) {
>> 692 /* Stupid approach */
>> 693 cli();
>> 694 sti();
>> 695 }
>> 696 }
>> 697
>> 698 static inline void get_irqlock(int cpu)
>> 699 {
>> 700 unsigned int loops = MAXCOUNT;
>> 701
>> 702 if (test_and_set_bit(0,&global_irq_lock)) {
>> 703 /* do we already hold the lock? */
>> 704 if ((unsigned char) cpu == global_irq_holder)
>> 705 return;
>> 706 /* Uhhuh.. Somebody else got it. Wait.. */
>> 707 do {
>> 708 do {
>> 709 if (loops-- == 0) {
>> 710 printk("get_irqlock(%d) waiting, global_irq_holder=%d\n", cpu, global_irq_holder);
>> 711 #ifdef CONFIG_XMON
>> 712 xmon(0);
>> 713 #endif
>> 714 }
>> 715 } while (test_bit(0,&global_irq_lock));
>> 716 } while (test_and_set_bit(0,&global_irq_lock));
>> 717 }
>> 718 /*
>> 719 * We also need to make sure that nobody else is running
>> 720 * in an interrupt context.
>> 721 */
>> 722 wait_on_irq(cpu);
>> 723
>> 724 /*
>> 725 * Ok, finally..
>> 726 */
>> 727 global_irq_holder = cpu;
>> 728 }
>> 729
>> 730 /*
>> 731 * A global "cli()" while in an interrupt context
>> 732 * turns into just a local cli(). Interrupts
>> 733 * should use spinlocks for the (very unlikely)
>> 734 * case that they ever want to protect against
>> 735 * each other.
>> 736 *
>> 737 * If we already have local interrupts disabled,
>> 738 * this will not turn a local disable into a
>> 739 * global one (problems with spinlocks: this makes
>> 740 * save_flags+cli+sti usable inside a spinlock).
>> 741 */
>> 742 void __global_cli(void)
>> 743 {
>> 744 unsigned long flags;
>> 745
>> 746 __save_flags(flags);
>> 747 if (flags & (1 << 15)) {
>> 748 int cpu = smp_processor_id();
>> 749 __cli();
>> 750 if (!local_irq_count(cpu))
>> 751 get_irqlock(cpu);
>> 752 }
>> 753 }
>> 754
>> 755 void __global_sti(void)
>> 756 {
>> 757 int cpu = smp_processor_id();
>> 758
>> 759 if (!local_irq_count(cpu))
>> 760 release_irqlock(cpu);
>> 761 __sti();
>> 762 }
>> 763
>> 764 /*
>> 765 * SMP flags value to restore to:
>> 766 * 0 - global cli
>> 767 * 1 - global sti
>> 768 * 2 - local cli
>> 769 * 3 - local sti
>> 770 */
>> 771 unsigned long __global_save_flags(void)
>> 772 {
>> 773 int retval;
>> 774 int local_enabled;
>> 775 unsigned long flags;
>> 776
>> 777 __save_flags(flags);
>> 778 local_enabled = (flags >> 15) & 1;
>> 779 /* default to local */
>> 780 retval = 2 + local_enabled;
>> 781
>> 782 /* check for global flags if we're not in an interrupt */
>> 783 if (!local_irq_count(smp_processor_id())) {
>> 784 if (local_enabled)
>> 785 retval = 1;
>> 786 if (global_irq_holder == (unsigned char) smp_processor_id())
>> 787 retval = 0;
>> 788 }
>> 789 return retval;
>> 790 }
>> 791
>> 792 int
>> 793 tb(long vals[],
>> 794 int max_size)
>> 795 {
>> 796 register unsigned long *orig_sp __asm__ ("r1");
>> 797 register unsigned long lr __asm__ ("r3");
>> 798 unsigned long *sp;
>> 799 int i;
>> 800
>> 801 asm volatile ("mflr 3");
>> 802 vals[0] = lr;
>> 803 sp = (unsigned long *) *orig_sp;
>> 804 sp = (unsigned long *) *sp;
>> 805 for (i=1; i<max_size; i++) {
>> 806 if (sp == 0) {
>> 807 break;
>> 808 }
>> 809
>> 810 vals[i] = *(sp+1);
>> 811 sp = (unsigned long *) *sp;
>> 812 }
>> 813
>> 814 return i;
>> 815 }
>> 816
>> 817 void __global_restore_flags(unsigned long flags)
>> 818 {
>> 819 switch (flags) {
>> 820 case 0:
>> 821 __global_cli();
>> 822 break;
>> 823 case 1:
>> 824 __global_sti();
>> 825 break;
>> 826 case 2:
>> 827 __cli();
>> 828 break;
>> 829 case 3:
>> 830 __sti();
>> 831 break;
>> 832 default:
>> 833 {
>> 834 unsigned long trace[5];
>> 835 int count;
>> 836 int i;
>> 837
>> 838 printk("global_restore_flags: %08lx (%08lx)\n",
>> 839 flags, (&flags)[-1]);
>> 840 count = tb(trace, 5);
>> 841 printk("tb:");
>> 842 for(i=0; i<count; i++) {
>> 843 printk(" %8.8lx", trace[i]);
>> 844 }
>> 845 printk("\n");
>> 846 }
>> 847 }
>> 848 }
>> 849 #endif /* CONFIG_SMP */
>> 850
>> 851 static struct proc_dir_entry *root_irq_dir;
>> 852 static struct proc_dir_entry *irq_dir[NR_IRQS];
>> 853 static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
>> 854
>> 855 #ifdef CONFIG_IRQ_ALL_CPUS
>> 856 #define DEFAULT_CPU_AFFINITY 0xffffffff
>> 857 #else
>> 858 #define DEFAULT_CPU_AFFINITY 0x00000001
>> 859 #endif
>> 860
>> 861 unsigned int irq_affinity [NR_IRQS] =
>> 862 { [0 ... NR_IRQS-1] = DEFAULT_CPU_AFFINITY };
>> 863
>> 864 #define HEX_DIGITS 8
>> 865
>> 866 static int irq_affinity_read_proc (char *page, char **start, off_t off,
>> 867 int count, int *eof, void *data)
>> 868 {
>> 869 if (count < HEX_DIGITS+1)
>> 870 return -EINVAL;
>> 871 return sprintf (page, "%08x\n", irq_affinity[(int)data]);
>> 872 }
>> 873
>> 874 static unsigned int parse_hex_value (const char *buffer,
>> 875 unsigned long count, unsigned long *ret)
>> 876 {
>> 877 unsigned char hexnum [HEX_DIGITS];
>> 878 unsigned long value;
>> 879 int i;
>> 880
>> 881 if (!count)
>> 882 return -EINVAL;
>> 883 if (count > HEX_DIGITS)
>> 884 count = HEX_DIGITS;
>> 885 if (copy_from_user(hexnum, buffer, count))
>> 886 return -EFAULT;
>> 887
>> 888 /*
>> 889 * Parse the first 8 characters as a hex string, any non-hex char
>> 890 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
>> 891 */
>> 892 value = 0;
>> 893
>> 894 for (i = 0; i < count; i++) {
>> 895 unsigned int c = hexnum[i];
>> 896
>> 897 switch (c) {
>> 898 case '' ... '9': c -= ''; break;
>> 899 case 'a' ... 'f': c -= 'a'-10; break;
>> 900 case 'A' ... 'F': c -= 'A'-10; break;
>> 901 default:
>> 902 goto out;
>> 903 }
>> 904 value = (value << 4) | c;
>> 905 }
>> 906 out:
>> 907 *ret = value;
>> 908 return 0;
>> 909 }
>> 910
>> 911 static int irq_affinity_write_proc (struct file *file, const char *buffer,
>> 912 unsigned long count, void *data)
>> 913 {
>> 914 int irq = (int) data, full_count = count, err;
>> 915 unsigned long new_value;
>> 916
>> 917 if (!irq_desc[irq].handler->set_affinity)
>> 918 return -EIO;
>> 919
>> 920 err = parse_hex_value(buffer, count, &new_value);
>> 921
>> 922 /*
>> 923 * Do not allow disabling IRQs completely - it's a too easy
>> 924 * way to make the system unusable accidentally :-) At least
>> 925 * one online CPU still has to be targeted.
>> 926 *
>> 927 * We assume a 1-1 logical<->physical cpu mapping here. If
>> 928 * we assume that the cpu indices in /proc/irq/../smp_affinity
>> 929 * are actually logical cpu #'s then we have no problem.
>> 930 * -- Cort <cort@fsmlabs.com>
>> 931 */
>> 932 if (!(new_value & cpu_online_map))
>> 933 return -EINVAL;
>> 934
>> 935 irq_affinity[irq] = new_value;
>> 936 irq_desc[irq].handler->set_affinity(irq, new_value);
>> 937
>> 938 return full_count;
>> 939 }
>> 940
>> 941 static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
>> 942 int count, int *eof, void *data)
>> 943 {
>> 944 unsigned long *mask = (unsigned long *) data;
>> 945 if (count < HEX_DIGITS+1)
>> 946 return -EINVAL;
>> 947 return sprintf (page, "%08lx\n", *mask);
>> 948 }
>> 949
>> 950 static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
>> 951 unsigned long count, void *data)
>> 952 {
>> 953 unsigned long *mask = (unsigned long *) data, full_count = count, err;
>> 954 unsigned long new_value;
>> 955
>> 956 err = parse_hex_value(buffer, count, &new_value);
>> 957 if (err)
>> 958 return err;
>> 959
>> 960 *mask = new_value;
>> 961 return full_count;
>> 962 }
>> 963
>> 964 #define MAX_NAMELEN 10
>> 965
>> 966 static void register_irq_proc (unsigned int irq)
>> 967 {
>> 968 struct proc_dir_entry *entry;
>> 969 char name [MAX_NAMELEN];
>> 970
>> 971 if (!root_irq_dir || (irq_desc[irq].handler == NULL) || irq_dir[irq])
>> 972 return;
>> 973
>> 974 memset(name, 0, MAX_NAMELEN);
>> 975 sprintf(name, "%d", irq);
>> 976
>> 977 /* create /proc/irq/1234 */
>> 978 irq_dir[irq] = proc_mkdir(name, root_irq_dir);
>> 979
>> 980 /* create /proc/irq/1234/smp_affinity */
>> 981 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
>> 982
>> 983 entry->nlink = 1;
>> 984 entry->data = (void *)irq;
>> 985 entry->read_proc = irq_affinity_read_proc;
>> 986 entry->write_proc = irq_affinity_write_proc;
>> 987
>> 988 smp_affinity_entry[irq] = entry;
>> 989 }
>> 990
>> 991 unsigned long prof_cpu_mask = -1;
>> 992
>> 993 void init_irq_proc (void)
>> 994 {
>> 995 struct proc_dir_entry *entry;
>> 996 int i;
>> 997
>> 998 /* create /proc/irq */
>> 999 root_irq_dir = proc_mkdir("irq", 0);
>> 1000
>> 1001 /* create /proc/irq/prof_cpu_mask */
>> 1002 entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
>> 1003
>> 1004 entry->nlink = 1;
>> 1005 entry->data = (void *)&prof_cpu_mask;
>> 1006 entry->read_proc = prof_cpu_mask_read_proc;
>> 1007 entry->write_proc = prof_cpu_mask_write_proc;
>> 1008
>> 1009 /*
>> 1010 * Create entries for all existing IRQs.
>> 1011 */
>> 1012 for (i = 0; i < NR_IRQS; i++) {
>> 1013 if (irq_desc[i].handler == NULL)
>> 1014 continue;
>> 1015 register_irq_proc(i);
>> 1016 }
>> 1017 }
>> 1018
>> 1019 void no_action(int irq, void *dev, struct pt_regs *regs)
>> 1020 {
38 } 1021 }
39 1022
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